I use PhysX to make vehicle, and I faced strange problem with wheels behavior (same I found in kings on wheels from samples folder). Wheels aren't changing they position smoothly (in Z coordinates), so if you drive on low-poly map (made with model) you can see some strange behavior, like jerking while adapting to slopes and surface angles.. I can provide demo, video and better explanation if needed, but I really want this to be fixed, so it will act smoothly as it used to in ODE.

EDIT: got some mistakes..